Check Your Plumbing — Most older homes were built with copper pipes soldered together with toxic lead, or actual lead pipes. Over time, the lead dissolves into your drinking water, threatening the health of your family. Health officials often recommend that homeowners in this situation let the tap run for a few minutes before using the water for drinking or cooking, to flush clean water through the lines, but this method wastes water and is not guaranteed to achieve safe water quality. You can also replace the toxic pipes, but a less costly option would be to install a water filter. Be sure to check whether the brand of filter is certified and proven to remove lead (see below), because some filters won't remove dissolved metals.

Study Your Local Water System — Each year, community water utilities produce a Consumer Confidence Report (CCR), which provides information about that utility's drinking water sources, and the treatment methods they use. The report includes data on the quality of the water provided during the previous year, and they are required to report any violations of health standards for chemical contaminants or pathogens.

Check and Maintain Your Well System — If you drink water from a private well, it's important to maintain it properly and check for contaminants.

Have Water Samples Analyzed — Many companies offer packaged water tests which can tell you a great deal about your water quality. Costs generally increase if you request that the test cover a larger number of chemical types, bacteria and/or viruses. Testing for a few "indicator" chemicals or organisms may tell you whether a broader test is necessary.

Install a Water Filter — If you have unavoidable contaminants in your tap water, or would simply appreciate the extra security, you can install a water filter on your kitchen faucet, your shower, or your entire household water system. Many companies offer a variety of filter types, with varying effectiveness and costs.

Contact Your Elected Officials With Your Concerns — Though public drinking water systems are generally reasonably safe, our government regulations of drinking water supplies are often not as comprehensive or as well enforced as we might hope. Some drinking water health standards have been politically compromised, while many chemicals have no drinking water standards at all. Testing frequency is often limited due to budget constraints. And underground water supplies are often not protected from excessive withdrawals by high-capacity wells or other threats nearby. We all need to tell our elected officials that water supplies and water quality are extremely important to us, and must be protected.

In some localities, drinking water drawn from underground aquifers can become contaminated with bacteria and viruses because of insufficient topsoil layers to filter rainwater as it trickles down to recharge the groundwater. Livestock manure, human sewage sludge, fertilizers and pesticides can also seep down into groundwater supplies. In some areas contaminated surface runoff can directly enter underground water supplies through fractured rock outcroppings, sink holes, quarries and abandoned wells.

To make matters worse, large areas of the US suffer from naturally high levels of toxic minerals and contaminants - such as arsenic, lead, fluoride, iron and radium — in certain layers of the underground aquifer. When these toxic layers are drilled through or pumped, the contaminants can spread into clean aquifer layers resulting in wider groundwater contamination problems.

Unfortunately, efforts to treat water can also result in new health threats. Chlorination of drinking water supplies virtually eliminates most disease or bacterial contamination, but creates traces of several toxic by-products in drinking water - such as chloroform, chloramines, trihalomethanes and other chlorinated organic compounds. Fluorination of drinking water is used to prevent tooth decay, but may also have unintended and unhealthy side effects. Government agencies have decided the benefits are worth the risks, but alternatives are available in many instances.

These are serious problems, but most can be addressed.

Unlike municipal water sources, no regulations exist requiring the regular testing of private water wells. Consequently, the responsibility for monitoring water quality and identifying potential health risks to family members falls upon the homeowner.
If you do rely on a private water well for your drinking water, it is recommended that it be tested regularly. The nature of aquifers makes them particularly vulnerable to contamination from a variety of land-uses including industry, manufacturing and agriculture. While you may follow some basic practices to prevent contamination such as (1) maintaining your septic system, (2) properly disposing household hazardous wastes, (3) judiciously applying fertilizers and pesticides and (4) reducing your use of household hazardous wastes, there is no guarantee that your neighbor or anyone else who can contaminate the same aquifer is doing likewise.
It is important to note that contaminated water does not necessarily taste, smell or look any different from safe drinking water. For example, you cannot taste or smell inorganic arsenic, nitrates, coliform bacteria and organic compounds such as PCB's and PBB's in your drinking water. The only way to detect these substances and others like them is by testing your well water.